<script>
  function GrandParent() {
    this.name = 'grandparent'
    this.card = 'visa'
  }
Parent.prototype=new GrandParent()
  function Parent() {
    this.lastName = '张'
  }
Child.prototype=new Parent()
  function Child() {
    this.name = '张三'
    this.age = 18
  }

  const c = new Child()

  //console.log(c.lastName) // 张
  console.log(c.card)  // visa


</script>